Spray painting apparatus



Jan. 5, 1965 H. v. VEUM SPRAY PAINTING APPARATUS 2 Sheets-Sheet 1 I Filed Oct. 1, 1962 l l I I I I I I I I I I I I I I I l I J Jan. 5, 1965 H. v. VEUM SPRAY PAINTING APPARATUS 2 Sheets-Sheet 2 Filed Oct. 1, 1962 NNN QNN

IN VENTOR. bfqez. 4N0 K VEUM fi m/exams United States Patent w 3,164,325 SPRAY PAINTENG APPTUS Harland V. Veurn, Whittier, Calif., assignor to Edwards S. Sawyer, Eugene, Greg. Filed Oct. 1, 1%2, Ser. N 227,473 11 Claims. (Cl. 239-126) This invention relates in general to spray painting, and more particularly to apparatus for direct spray application of coating compositions to surfaces without employment therewith of compressed air or the like gases. Some of the coating compositions which can be applied in accordance with this invention include materials which may be more specifically defined as varnishes, vinyls, lacquers, enamels, plastics, and the like, as Well as texture and acoustic materials and those generally termed paint.

Heretofore and at the present time, compressed air is generally employed through suitable nozzle devices as the means for atomizing the coating material and directing the resultant finely dividedspray toward the working surface to be coated. For such purpose, relatively large volumes of air at pressures of from approximately 40 to 80 lbs. per square inch are usually required. Even under the best of such conditions, it is necessary to use not only relatively large volumes of air, but also relatively large proportions of thinners or solvents in most of the coating materials in order to reduce the viscosity sufficiently and otherwise modify the fluid characteristics of the coating composition such that it will flow to the nozzle device at the proper rate and interact with the air stream to form a finely divided spray of adequate solidity, volume, and form.

Such combined requirements for both relatively large volumes of spray air and solvent thinners have a number of disadvantages. First, the relatively large proportion of thinner or solvent required to be used greatly increases the total initial cost of the coating material. Secondly, because of the relatively large volume and high velocity of the air associated with such conventional air spray devices, a considerable proportion of the coating material in and surrounding the spray is propelled in the form of a light, fog-like stream, and because such air stream obviously cannot penetrate the working surface toward which it is directed, but must be largely deflected before reaching such surface, the fog of coating material is thereby likewise deflected by the deflected air stream from the course of the spray and never impinges upon the working surface. A large percentage of the coating material is thus carried away and dissipated in the surrounding air in the form of a fine dust. Thirdly, the cooling effect resulting from release of the spray air undesirably cools the coating composition and tends to cause condensation of water vapor both within the spray and on the surface to which the spray is applied, which is detrimental to the quality and appearance of the resultant coating.

Additionally, the continuous requirement for large ,volumes of pressure air represents an appreciable power demand, which is inherently inefiiciently utilized and which further adds to the cost of the coating operations. Furthermore, the conventional air spray method of coating the interior of relatively'small enclosures or containers is impractical in many cases, "as those experienced in the art will appreciate.

Attempts heretofore made to eleminate the use of compressed air in connection with so-called spray painting have been unsatisfactory for a number of reasons, among them being the practical difficulties of applying sufiicient pressure to and successfully pumping the kind offluids or semi-plastic coating compositions involved. The fluid handling, pumping, and controlling equipment heretofore employed has been subject to operational difliculties and Patented Jan. 5, 1965 rapid wear and deterioration. Among the operational difiiculties encountered has been the lack of uniformity and control of the pressures involved, when apparatus of otherwise practical design has been used. By this is meant that when relatively high speed pulsationless types of high pressure pumping equipment is attempted to be used, it is found to be extremely unsuited to the intermittent handling of relatively small quantities of viscous and sometimes abrasive coating compositions. On the other hand, when relatively low speed pumping equipment, such as conventional reciprocating pumps are used, which are more suited for handling these materials, relatively high amplitude pressure pulsations and non-uniform pressures usually result. Contributing largely to such difficulties are the requirements for the pumping equipment to handle intermittently a relatively low and extremely variable volume of viscous coating material at relatively high pressure. Also, such systems were heretofore very diflicult, if not impracticable to clean up, that is, to purge all the relatively complicated internal parts after use.

It is, therefore, an object of this invention to eliminate the hereinbefore mentioned difiiculties and disadvantages heretofore associated with conventional spray coating methods and apparatus.

It is an object of this invention to furnish a spray paint-. ing system which generally raises the efficiency of transfer of the coating compositions to the working surfaces to be coated.

It is another object of this invention to furnish a spray painting system, in which the requirements for use of thinners in the coating compositions is minimized together with the attendant reducton in cost.

It is another object of this invention to supply a spray coating system, in which the use of compressed air is eliminated, thereby eliminating the waste of coating composition inherently associated with such use of compressed a1r.

It is still another object of this invention to present a spray painting system of increased efficiency and in which the power requirements for its operation are reduced.

It is a further important object of this invention to furnish a coating composition pumping and pressurizing system, which has superior operating characteristics in regard to accurate control of output pressure and freedom from pressure variations and pulsations.

It is also an object of this invention to furnish a socalled spray painting system as aforesaid, in which the apparatus is more durable and troublefree.

The objects of this invention are in general attained by a system, in which the use of compressed air or the like gas is completely eliminated and high pressurization of the coating composition itself is solely employed for atomizing and forming the coating material spray. The objects are also attained by the use of fluid pressurization means, which is of improved efliciency and in which the working parts are of relatively slow or low velocity in so far as its relation to or contact with the coating composition is concerned, combined with novel and improved control means formaintaining the output of such pressurization means at a constant pressure, freefrom pulsations.

These and other objects, advantages, and features of novelty will be evident hereinafter.

in the drawings, which illustrate a preferred embodiment and mode of operation of the invention and in which like reference characters designate the same or similar parts through the several views:

FIGURE 1 is a view partly diagrammatic and partly in longitudinal section of the general assembly of the apparatus and illustrating one stage of its operation.

FIGURE 2 is a view of a fragmentary portion of the apparatus of FIGURE 1 and illustrating another stage of its operation.

FIGURES is an enlarged detail rear elevational view of a portion of the valving apparatus of FIGURES l and 2.

Apparatus I positivedisplacement pump 12 is connected through pipe 14h) 'a filter which is submerged in the body of oil 18 within the reservoir iii. Thedischarge of pump 12 is connected through pipes 29 and 22 to an inlet-outlet connection 24 in the bottom of an accumulator 24? which is preferably of the conventional bladder type. The oil pressure line 20 and accumulator 26 are, in turn, connected through pipe 2%, pressure regulator 36, and branch pipe 32 to the pressure inlet port connection 34 of a fourway, rotary pilot valve 36. The oil pressure line 2% and accumulator 2d are also connected by 'way of pipe 2 8, pressure regulator 34 and branch pipe 4% to the pressure inlet 42 of a four-way, piston type control valve 44-, the construction and operation of which is; described hereinafter. 1

The discharge or exhaust connection 46 of the control valve 44 is connectedby way of return lines 48. and 49 .to return pipe which enters the oil reservoir ill. The

discharge or exhaust connection 52 of the before mentioned four-way pilot valve 36 likewise makes return connection through lines 54 and as to the return pipe 5th which enters the oil reservoir 10. An automatic pressure relief,

unloading valve 56 and a manually operable bypass valve 58 interconnect theoil pump pressure discharge line 2% with the return line 49. A pressure gauge 47 is connected through pipe 51 to the oil pressure line 45 The four-way control valve 44 is constructed with an elongated inner bore 64), which contains three axially spaced apart cylindrical valve spools 62, 64, and as interconnected for simultaneous axial movement within the bore 69 by a common axial piston rod 68, one end of which extends outwardly through an end thereof and into a pilot cylinder 76 wherein it is connected to a pilot piston '72. Opposite internal ends 74 and 76 of the pilot cylinder 7t), onopposite sides of the piston 72, are connected through pipes 78 and 8t respectively, to opposite port connections 82 and 84 of the four-way pilot valve 36.

The bore oil of the control valve 44 is provided with five annular axially spaced apart ports, namely, an outermost pair of exhaust ports 88 and -ll, an inner, opposite pair of pressure inlet and outlet control ports 92 and 94, and a central pressure inlet port 96, The before mentioned pressure line; 40 makes connection at 4-2 with the said pressure inlet port as, as before mentioned. The exhaust ports 83 and 95B are connected through a common internal manifold passage Till} with the beforementioned exhaust connection as which is, in turn, connected through pipe 48 and line 49 to return connection 5%? to the oil reservoir iii, as before described.

The inletand outlet ports 5*2 and $4 of the control valve 44 make connection respectively through pipes Hi2 and 194 with inlet connections 1% and 1%, which lead through internal head passages 11% and 112. to the opposite internal ends 114 and 116 of a relatively large hydraulic actuating cylinder l2tlL- The actuating cylinder 12s contains a piston 122 attached to the inner end of a piston rod 124, which extends outwardly through a packing gland 126 in the rod end of the hydraulic cylinder for connection with the pistonrod of an opposite pressurizing cylinder, as hereinafter more fully described.

Referring next primarily to the before mentioned coating composition pressurizing system apparatus shown within the dotted enclosure B of the drawings, the pressurizing cylinder previously referred to is shown at 1311. The pressurizing cylinder lfitl contains in its bore a piston 132 connected to the inner end of a piston rod 134 which, in turn, passes out through the rod end of the cylinder through a packing gland 13d and makes coaxial coupling at 138 wth the before mentioned piston rod 12.4 extending from the piston 122 of the actuting cylinder 12% Opposite inner ends 140 and 142 of the pressurizing cylinder 13%? on opposite sides of the piston 132 make connection by Way of internal head passages M4 and 14d, respectively, to exterior connections 148 and 15$.

A coating composition feed and circulation pump 152 has its inlet connection i554 connected through suction pipe 156, filter 158 to a flexible suction hose tea, the inlet end 162 of which is adapted to be placed in a body of coating material, as shown at 164 contained within a suitable container, such as a can or drum laid.

The discharge 168 of the feed pump 152 is connected through pipe feed 1'76 and thence through opposite check valves 172 and 174 and manifold feed pipes 1'76 and 178 to the before mentioned connection inlets 148 and 154), respectively, at opposite ends or" the pressurizing cylinder 53% The check valves 172 and 174 act in the manner indicated by the arrows shown thereon to permit the coating composition to flow therethrough to the opposite ends of the cylinder in the directions indicated by the arrows, but to prevent flow therethrough in the opposite directions. The discharge line 178 of the pump 152 is also connected by way of manifold pipe 180 to an adjustable back pressure relief valve 182 which, in turn, is connected through a return pipe 184 to a flexible hose 186, the opposite end of which is, in turn, adapted to be placed within the before mentioned container 166 for return and recycling of coating composition from the feed pump, as hereinafter described. For convenience, the flexible suction hose lot} and return hose 182 may be mechanically attached together by suitable clip means IS&

The before mentioned connections 148 and 15d of the pressurized cylinder 1% are also connected respectively through check valves 1% and 192 to a discharge line 194 provided at the end thereof with a hose connection 1%. In operation, spray gun, as illustrated generally at 200, is connected through a suitable high pressure hose 1% to the hose connection 1% from which it receives its supply of pressurized coating composition. The coating composition discharge line 194 is also connected through a pipe 232 to a pressure accumulator 204 adapted to contain a volume of entrapped air for the purpose of smoothing out pulsations and maintaining a relatively uniform pressure of the coating composition fed to the spray gun 22%.

The oil pressurizing pump 12 and the coating composition feed pump 152 are drivingly connected through separate belt drives 2% and 208, which extend respective- 131 between pulley 21%- on the drive shaft of pump i2 and pulley 212 on the drive shaft of the feed pump 152 and pulleys at 23 2- on the shaft of a suitable prime mover, such as a gasoline engine, as indicated at 2%.

Extending laterally from the coupling 138, which interconnects the piston rods 124 and 234 of the cylinders 12% and 136, respectively, is a flange member 22%. Mounted adiacent the flange member 22% intermediate the confronting ends of the cylinders 12% and 13% on a parallel guide member 222 is an axially reciprocable sleeve 224. The sleeve 224 is provided with annular stop flanges 22-6 and 228 on opposite ends thereof, which are positioned to be engaged by flange 2% adjacent the opposite limits of reciprocation of the piston rods 124 and 134 as a unit, thereby to shiftthe sleeve 224 axially on the guide member 222 within predetermined axial limits. Extending from an intermediate portion of the sleeve 224 is a control arm 230, the outer cylindrical end of which engages the groove formed between opposite radial fingers 232 and 234 forming the outer end of a forked lever 236. The opposite end of lever 236 is fixed to a shaft 238, which extends into the interior of the four-way control valve 56 and is coupled to the interior plug valve portion thereof shown at 246, for rotation of such plug valve portion 240 between valving limits, as hereinafter specified. The plug portion 244 of the control valve 36 is provided with a pair of diametrically opposite passages 242 and 244 adapted to perform a valving interconnecting action between the several. control valve ports and connections 52, 82, 34, and 84, as hereinafter more fully described in connection with the operation of the apparatus.

Operation To initiate the operation of the hereinhefore described spray system, the bypass valve 58 is first opened, after which the engine 26d is started which drives both the oil pump 12 and the coating composition feed pump 152. The oil pump 12 withdraws oil from the reservoir lltl through the filter 1d and suction pipe 14 and discharges it into the pressure line 20 and thence through the opened bypass valve 58 and return through pipes 49 and 50 to the oil reservoir. After the oil pump 12 has thus been put into operation, the bypass valve 58 is closed, and immediately thereafter, in the absence of a demand for 6 the coil return exhaust lines 49 and 50 by way of passage 11% cylinder connection 146, pipe 102, valve port 92, and through the open interval intermediate the valve spools 62 and 64 to the manifold passage 100, valve exhaust connection 46, and pipe 48.

The differential pressure thus applied across the piston 122 in the actuating cylinder 12%) tends to-move it in the coupling 133 into engagement with the stop flange 218 discharge of'coating composition from the spray gun 230, 3

the oil pressure in the pressure line 26 builds up to a value determined by the adjustment of the unloading bypass valve 56. The unloading valve 56ris then adjusted until the desired pressure is maintained in the pressure line-2t). The oil pump 12. and the unloading valve 56 are preferably such that a substantially constant pressure of 2200 lbs. may be maintained in the pressure line 20.

The pressure in line 2i and oil therein is transferred through pipe 22 to the accumulator 26 in sufficient quantity to bring the pressure in the accumulator 26 up to the same pressure as that existing throughout line 29. This oil pressure is communicated through pipe connection 28 to the pressure regulator valve 30 and thence through one branch pipe 32 to the pressure inlet port connection 34 of pilot valve 36, and through the other branch pipe to the pressure inlet 42 of the pilot operated control valve 44, both at a suitable pressure determined by the pressureregulating valve 31 and as indicated by the pressure gauge 47 in accordance with the pressure requirements of the particular coating composition to be applied to the spray gun 2%. Normally, for most coating compositions, the-regulator valve 30 is adjusted to give an oil pressure in pipes 32 and 40- in the order of 50 to 2200 lbs. per square inch.

Assuming the pilot valve 36 initially to be in the position shown in FIGURE 1, oil is transferred under pressure through branch pipe 32, inlet port connection 34, valve passage 244, port connection 84, and pipe 8t) into the end 76 of the pilot cylinder '70, and the opposite end 74 of the pilot cylinder 79 is connected through pipe 73, pilot valve port connection 82, pilot valve passage 242, pilot valve port connection 52 to pipe 54 and thence through return pipe lines 49 and 50 to the oil reservoir 19. Under the latter conditions, the piston 72 in the cylinder 7 9 is immediately forced to the extreme left hand position, and thereby moves the valve spools 62, 64, and 66 within the bore 68 of the control valve likewise to their extreme left hand positions, all as shown in FIGURE 1. In this latter position of the valving mechanism of the control valve 44, the oil under pressure, which flows through the pressure regulator 39, is free to flow through branch pipe 40, control valve pressure inlet 42, valve port 96, and thence through the opening interval between valve spools 64 and 66 and out through port 94, pipe 104, through cylinder connection 163 and passage 112, into the right hand end 166 of the actuating cylinder 120. At the same time, the left hand end 114 of the actuating cylinder 12% is put into communication with on the left hand end of sleeve 224, the arm 23% carried thereon will engage the finger 234 and thereby cause the valve lever 236 to be moved, such as to rotate the central plug portion 246 of the pilot valve 36 in a counterclockwise, direction from the position shown in FIGURE 1 v to the position shovm in FIGURE 2, or as illustrated in FIGURE 3, from the position shown in solid lines to the position shown in broken lines. 1

' With the plug portion 244) of the pilot valve 36 thus under pressure, which passes through pressure regulator valve 3% will then flow through branch pipe 32 into pilot valve inlet port, connection 34, through valve passage 244,

. out at pilot valve port connection 82, and through pipe 78 into the left hand end 74 of pilot cylinder '70, and the right hand inner end 76 of pilot cylinder 79 will at the same time be connected through pipe 84 to the pilot valve port connection 84, through valve passage 242, out of pilot valve port connection 52, and through pipe 54 to V the return lines 49 and 5d, and thence to the oil reservoir 10. Under the latter conditions, the piston 72 in the pilot cylinder 71 will be immediately forced into its extreme right hand position, as shown in FIGURE 2, and will like-wise position the valve spools 62, 64, and 66 also in their most right hand position within the bore Gil of the control valve 44. With the valve spools 62, 64, and 66 of the control valve 44 thus positioned, oil under pressure can then flow through the pressure regulator valve 30 and branch pipe 4th, into control valve pressure inlet 42, through control valve inlet port 96, through the interval immediate the valve spools 62 and 64 to the port ?2, and thence out through pipe 102 and into conection 1%, through passage into the left hand end 114 of the actuating cylinder 120. The opposite right hand end 116 of the actuating cylinder 120 is at the same time put in exhaust communication with the oil reservoir return lines 49 and 50 by way of the passage 112 in the end of actuating cylinder 12d, out through connection 108, through pipe 104, and into port 94 of the control valve '44, and thence through the interval between the valve spools 64 and 66 to the exhaust port 96 and from there out through the exhaust manifold passage ltitl and pipe 48 to the before mentioned return lines 49 and 50.

Under the latter conditions, the differential pressure applied across the piston 122 of the actuating cylinder 120 is such as to tend to move it in a right hand direction, as indicated by the arrow 119, as viewed in FIGURE 2.

Such motion will be intermittent and at a relatively slow rate depending upon the occurrence, frequency, and rate of demand ofcoating composition from the pressurizing cylinder 130, as controlled by the spray device 290.

- When such latter motion occurs, the piston rods 3.23

and 134, the coupling 138, and the flange 22d) carried thereby are likewise moved in a right hand direction until positions within the cylinders 129 and 135?, the plug of the pilot valve is correspondingly rotaL'onally moving back and forth between the valving positions illustrated in FIGURES 1 and 2 and in enlarged detail in FIGURE 3, thereby valving the actuating oil alternately to opposite sides of the pistonlZZi in opposite, ends of the actuating cylinder lit and thereby causing reciprocating movement of the piston 132 in the pressurizing cylinder 13%.

The coating composition feed and circulating pump 152 is driven by the engine 26%, and withdraws coating'composition from the container res through the suction hose res, filter 1513, pump inlet pipe 156, and pump inlet connection 154,- and discharges the coating composition from the purnpoutlet connection 168, through pipes 173 and 1&3, relief valve 132;, pipe 134i, and flexible hose 136 to the container laid. Normally, feed pump 15); is run at'a rate, and valve 182 adjusted, such. that thecoating composition is. circulated to and from the container see through the pump 152 at a rate which'is several times greater than the maximum demand for the spraying operation. The relief valve 182 is adjusted such as normally to result in a back pressure in feed line 17 1) of approximately 50 lbs. per square inch or whatever is required, depending upon the kind and character of coating composition being utilized, for adequate supply there? of to the pressurizingcylinder 13%. I

Assuming that the piston 132 in the cylinder 139 is beingIurged-in the left handdi'rection indicated by arrow 11$, asshown in FlGURE 1, the coating composition under pressure flows or tends to flow from the coating composition feed pump l2 through feed line 17b, and

thence through check valve 174, pump manifold pipe 178, to the inlet connection 15% at the right hand end of the cylinder 130, and thence in through the head passage 14d into the right handend of the cylinder I142. At the same time, pressure is applied by the action of the actuating cylinder, to the coating composition already present in the left hand endfl ltl of the cylinder 13%), which tends to force it out throughthe cylinder head passage 144, connection 14-8, and thence through check valve 19%, pipe 194, hose connection 1%, and through the flexible hose 1% to the spray gun 2%. Upon intermittent actuation of the valve in the spray gun 2%, with the resultant intermittent release of coating composition from the nozzle, the pressurizing piston R32, and consequently the actuating piston 122 are thereby correspondingly released for intermittent movement, the effective rate and distance of such resultant increments of movement being dependentupon the time and frequency of such intermittent operation of the spray gun 2%.

- Whenthe piston 132 has reached the limit of its left hand stroke in cylinder 13%, the valving mechanism is actuated, as before described, such as to cause the piston 32 to be urged to move toward the right hand end of the cylinder IlZlhand piston 132 likewise to be urged toward the-right hand end of cylinder 13%, and such fmotion will then result in coating composition under pressure in the supply line 17b from the feed pump 152, flowing or tending to flow through the check valve 372, manifold connection 176, into cylinder inlet 148, through cylinder passage 144, and thence into the space 144 in the left hand end of the cylinder 139; Meanwhile, while piston 132 is urged toward the right hand end of the cylinder 139, as before mentioned, pressure is thereby applied to the coating composition in the space 142 in the right hand end ofcylinder 136, which tends to force it to llow out through the cylinder passage 146, cylinder connection Mil, through manifold pipe 173, check valve 392 and pipe li l, to the hose connection 196, and thence through the flexible hose B0 to the spray gun 290.

The before in ntioned reciprocative or axial movements of piston 232 will, of course, only occur when and for so long as there is demand for coating composition at the spray gun 2% resulting from opening of the spray go" valve by means of manipulation of the valve trigger in a manner Well known in the art. When there is no demand for coating composition at the spray gun 2%, the coating composition continues to be continuously recycled and circulated by means of the feed pump 152 to and from the coating composition container 166, as hereinbelore mentioned, but the pistons 122 and 132 will remain stationary in cylinders 12b and lSt The accumulator which is connected through pipe 2% to the coating composition supply pressure pipe E4, entraps a body of air in the top thereof, and such air being at the average pressure of the coating composition being supplied, serves as a cushion or pressure reserve to make it possible to meet the sudden demands of the spray With the pistons 122 and 132; having equal diameters, as shown in the drawings, the pressure maintained by the system in the coating composition lines leading to the spray gun Elli; will be approximately equal to the pressure of the oil supplied from the oil pump i2 through the line 2%, as indicated by the pressure gauge 47 and as modified by pressure regulator 36, plus the pressure of the coating composition from feed pump 152, except for frictional losses in the system mainly in the actuating cylinder 12% and the pressurizing cylinder 13%. However, the oil in the pressurizing and circulating system need not necessarily be equal to the coating composition pressure in the coating composition circulating system, but the relation therebetween may be made any desired value depending upon the ratio of the diameter of piston 122 in actuating cylinder 12d and piston 32 in the prescylinder 13 An important advantage and feature of the pumping system, as hereinbefore described, resides in its operating characteristics, made possible by its novel pressurizing, feeding, and valving arrangement, which precludes the occurrence of any appreciable intervals of pressure drop or so-cslled dead center effects between pressurizing strokes of the piston pump. Thus, a substantially constant pressure is always maintained and available at the spray gun regardless of the rate and frequency of spraying operation. in normal operations, a pressure of the order of 2000 lbs. per square inch is maintained in the coating composition feed leading to the spray gun.

Specific apparatus, which has been found suitable for use as the principal components of the hereinbefore described apparatus are as follows. For the pilot valve, shown at 36 in the drawings, a Rotary Pilot Valve, Model No. 228A manufactured by the Hydraulic Power Division of The Hydraluic Press Mfg. Co., 'Mount Gilead, Ohio. For the four-way control valve, shown at 44 in the drawings, a Four-Way Valve, Model 2200-A%" manufactured by Hydraulic Power Division of The Hydraulic Press Mfg. 03., Mount Gilead, Ohio. For both the actuating cylinders, shown at 126 in the drawings, and the pressurizing cylinder, shown at 130 in the drawings, a 3 5. bore by 4" stroke Heavy Duty Hydraulic Cylinder, manufactured by Atlas Division of Sawyer Machine \VOl'lCS, Eugene, Oregon. For the oil pump, shown at 12 in the drawings, a Hydraulic Piston Pump, Cat. No. PP 3093-11, manufactured by Dynex, Incl, Pewaukee, Wisconsin. For the coating composition feed pump, shown at 152 in the drawings, a B 8: S No. 2S rotary gear pump, manufactured by Brown 8: Sharp Mfg. Co., Providence, Rhode island. For the pressure oil unloading valve, shown at as in the drawings. an Unloading Valve Part No. 6260543 SAE manufactured by Fluid Controls, Inc., Mentor, Ohio. For the paint supply bypass valve, shown at 182 in the drawings, a Relief Valve manufactured by Brown & Sharp Mfg. Co., Providence, Rhode Island. For the pressure reducing and regulating valve, shown at 30 in the drawings, a Pressure Reducing Valve, Model No. 2.300 manufactured by Hydraulic Power Division of The Hydraulic Press Mfg. 00., Mount Gilead, Ohio. For each of the check valves, shown at 172, 174, 190, and 192 in the drawings, a Pneu- Trol Check Valve No. 3000 /2" manufactured by Auto- Ponents, Inc, Belwood, Illinois. For the oil filter, shown at 16 in the drawings, a Suction Line Filter, Model No. 5 M 75 manufactured by Capital Engineering & Mfg. Co., Chicago, Illinois. The spray gun, shown at 200 in the drawings, may be any one of a number of suitable and well known components which may be purchased on the open market.

While the preferred embodiment of the invention has been herein disclosed, it is to be understood that the particular embodiment of the invention herein described, and shown in the drawings, is merely illustrative and not restrictive of the broad invention, and that many changes in design, structure, and arrangement may be made by those skilled in the art without departing from the scope of the invention, as defined in the appended claims.

What is claimed is:

1. In a coating composition pressurizing and spraying system, apparatus comprising:

a pump means including means for withdrawing actuating fluid from a reservoir containing actuating fluid and for discharging same therefrom under pressure through a first discharge means;

means for receiving coating composition from a container and conveying same under a given pressure to c. pressurizing inlet means;

pressurizing means for receiving coating composition from said pressurizing inlet means at said given pressure and simultaneously discharging same through a second discharge means at an increased pressure, said pressurizing means including:

a pressurizing cylinder, a pressurizing piston reciprocably contained in said pressurizing cylinder;

actuating means operative by actuating fluid received thereby under pressure from said first discharge means of said pump means for actuating said pressurizing means,

said actuating means including:

an actuating cylinder,

an actuating piston reciprocably contained in said actuating cylinder,

said pressurizing and actuating pistons being interconnected by a common means for simultaneous reciprocating movement respectively in said pressurizing cylinder and actuating cylinder;

pilot valve means;

control means actuated by said pistons, including lost motion means, for shifting said pilot valve means to opposite positions only adjacent the end of each opposite reciprocative travel of said pistons;

control valve means responsive to said shift of said pilot valve means for complete movement to opposite valving positions upon each said opposite shift of said pilot valve means, said pilot valve including means for receiving actuating fluid under pressure from said first discharge means and when in one such shifted position thereof admitting such actuating fluid under pressure to a first end of said actuating cylinder to urge said actuating piston to move in a direction therein toward the second end thereof, while permitting discharge of actuating fluid from the second end of said actuating cylinder to such reservoir, and when in the opposite such shifted posi- 1% tion admitting such actuating fluid under pressure to said second end of said actuating cylinder to urge said actuating piston to move in a direction therein toward the first end thereof, while permitting discharge of actuating fluid from said first end of said actuating cylinder to such reservoir;

means including valve means operative in connection with said pressurizing cylinder for admitting coating composition from said pressurizing inlet means to a first end of said pressurizing cylinder, and for simultaneously discharging coating composition under pressure from the second end of said pressurizing cylinder to said second discharge means when said actuating piston and thereby said pressurizing piston is being urged in one direction, therein;

and for admitting coating composition from said pressurizing inlet means to said second end of said pressurizing cylinder, and for simultaneously discharging coating composition under pressure from said first end of said pressurizing cylinder to said second discharge means when said actuating piston and thereby said'pressurizing piston is being urged in the other direction therein,

the movement of said pressurizing piston and consequently the movement of said actuating piston being controlled by and occurring only upon dicharge of coating composition from said second discharge means,

and means for connecting coating composition release and spray forming means to said second discharge means. I

2. In a coating composition pressurizing and spraying system, apparatus comprising:

a pump means including means for Withdrawing actuating fluid from a reservoir containing actuating fluid and discharging the same therefrom under a first pressure though a first discharge means;

means for maintaining said first discharge pressure substantially constant;

means for receiving coating composition from a container and conveying same to a pressurizing inlet connection means;

pressurizing means for receiving said coating composition through said inlet connection means and for discharging same through a second discharge means at increased pressure;

said pressurizing means including:

a pressurizing cylinder, a pressurizing piston reciprocably contained in said pressurizing cylinder,

and'actuating means operative by actuating fluid received thereby under pressure from said first dis charge means of said pump means;

said actuating means including:

an actuating cylinder,

an actuating piston reciprocably contained in said actuating cylinder,

said pressurizing and actuating pistons being interconnected by a common means for simultaneous reciprocating movement respectively in said pressurizing cylinder and actuating cylinder;

pilot valve means;

control means actuated by said pistons including lost motion means, for shifting said pilot valve means to opposite positions only adjacent the end of each opposite reciprocated travel of said pistons;

control valve responsive to said shift of said pilot valve means for complete movement to opposite valving positions upon each of said opposite shift of said pilot valve means, said pilot valve including means for receiving actuating fluid under pressure from said first discharge means and when in one such shifted position thereof admitting such actuating fluid under pressure to a first end of said actuating cylinder to urge said actuating piston to move in a direction therein toward the second end thereof, While permitting discharge of actuating fluid from the second end of said actuating cylinder to such reservoir, and when in the opposite such shifted position admitting such actuating fluid under pressure to said second end of said actuating cylinder to urge said actuating piston to move in a direction therein toward the first end thereof, While permitting discharge of actuating fluid from said first end of said actuating cylinder to such reservoir;

means including valve means operative in connection with said pressurizing cylinder for admitting coating composition through said inlet connection means to a first end of said pressurizing cylinder, and for simultaneously discharging coating composition under pressure from the second end of said pressurizing cylinder to said second discharge means when said actuating piston and pressurizing piston is being urged in one direction, as aforesaid, and for admitting coating composition through said inlet connection means to said second end of said pressurizing cylinder, and for simultaneously discharging coating composition under pressure from said first end of said pressurizing cylinder to said second discharge means When said actuating piston and pressurizing piston are being urged in the other direction, as aforesaid;

the movement of said pressun'zing piston and consequently the movement of said actuating piston thereby being effected by both the pressure of the actuating fluid and the pressure of the coating composition, and being controlled by and occurring only upon discharge of coating composition from said second discharge means,

and means for connecting coating composition release and spray forming means to said second discharge means.

3. In a coating composition pressurizing and spraying system, apparatus comprising:

said pressurizing means including:

a pressurizing cylinder, a pressurizing piston reciprocably contained in said pressurizing cylinder, actuating means operative by actuating fluid received thereby under pressure irom said first discharge means of said pump means for actuating said pressurizing means, said actuating means including: an actuating cylinder, an actuating piston reciprocably contained in said actuating cylinder, said pressurizing and actuating pistons being interconnected by a common means for simultaneous reciprocating movement respectively in said pressurizing cylinder and actuating cylinder; control valve means actuated by said pistons including lost motion means,tfor shifting said valve means to opposite positions only adjacent the end of each opposite reciprocative travel of said pistons, said control valve including means for receiving actuating fluid under pressure from said first discharge means and when in one. such shifted position thereof admitting such actuating fluid under pressure to a first end of said actuating cylinder to urge said actuating piston to move in a direction therein toward the second end thereof, While permitting discharge of actuating fluid from the second end of said actuating cylinder to such reservoir, and when in the opposite such shifted position admitting such actuating fluid under pressure to said second end of said actuating cylinder to urge said actuating piston to move in a direction therein toward the first end thereof, While permitting discharge of actuating fluid from said first end of said actuating cylinder to such reservoir;

means including valve means operative in connection with said pressurizing cylinder for admitting coating composition from said pressurizing inlet means to a first end of said pressurizing cylinder, and for simultaneously discharging coating composition under pressure from the second end of said pressurizing cylinder to said second discharge means when said actuating piston and thereby said pressurizing piston is being urged in one direction, therein;

and for admitting coating composition from said pressurizing inlet means to said second end of said pressurizing cylinder, and for simultaneously discharging coating composition under pressure from said first end of said pressurizing cylinder to said second discharge means when said actuating piston and thereby said pressurizing piston is being urged in the other direction therein,

the movement of said pressurizing piston and consequently the movement of said actuating piston being controlled by and occurring only upon discharge of coating composition from said second discharge means,

and means for connecting coating composition release and spray forming means to said second discharge means,

4. In a coating composition pressurizing and spraying system, apparatus comprising:

a first pump means for receiving fluid from a reservoir and discharging same at a first predetermined increased pressure;

a second pump means for receiving coating composition from a container and discharging same at a second predetermined increased pressure;

pressurizing means, connected to said first pump means and actuatable by said fluid discharged therefrom, for receiving said coating composition from said second pump means under said second predetermined pressure and simultaneously discharging said coating composition through discharge means at a third predetermined pressure greater than said second predetermined pressure;

and means for connecting spray forming means to said discharge means.

5. In a coating composition pressurizing and spraying system, apparatus comprising:

a first pump means for receiving fluid from a reservoir and discharging same at a first predetermined increased pressure;

a second pump means for receiving coating composition from a container and discharging same at a second predetermined increased pressure;

pressurizin g means, connected to said first pump means and actuatable by said fluid discharged therefrom, for receiving said coating composition from said second pump means under said second predetermined pressure and simultaneously discharging said coating composition through discharge means at a third predetermined pressure greater than said second predetermined pressure;

means for circulating coating composition from such container through said second pump means and return to such container at a rate greater than that at which said pressurizing means receives coating composition from said second pump means;

and means for connecting spray forming means to said discharge means.

6. In a coating composition pressurizing and spraying system, apparatus comprising:

a fluid reservoir; 1

a first pump means including means for receiving fluid from said reservoir and discharging same therefrom through a first discharge means;

unloading valve means interconnecting said first discharge means and said reservoir for bypassing fluid from said first discharge means to said reservoir when the fluid pressure in said first discharge means exceeds a first predetermined value;

a second pump means, including means for receiving coating composition from a container and discharging same through a second discharge means;

unloading valve means for interconnecting said second discharge means and such container for circulating coating composition from such container through said second pump means and return to such container when the coating composition in said second discharge means reaches a second predetermined pressure;

pressurizing means actuatable by said fluid discharged from said first pump means, for receiving said coating; composition from said second pump means through said second discharge means and simultaneously discharging same through a third discharge means at a final pressure greater than said second predetermined pressure; 7

and means for connecting spray forming means to said third discharge means.

are gees 7. In a coating composition pressurizing and spraying system, apparatus comprising:

an actuating fluid reservoir;

a first pump means for withdrawing actuating fluid from said reservoir and discharging same therefrom under pressure through a first discharge means;

adjustable unloading valve means interconnecting said first discharge means and said reservoir for bypassing actuating fluid from said first discharge means to said reservoir when the actuating fluid pressure in said first discharge means exceeds a first predetermined value;

a second pump means, including means for receiving coating composition from a container and discharging same through a second discharge means;

adjustable unloading valve means for interconnecting said second discharge means and such container for continuously circulating coating composition through said second pump means and such container when the coating composition in said second discharge means reaches a second predetermined pressure;

pressurizing means for receiving said coating composition from said second pump means through said second discharge means at said predetermined pressure and simultaneously discharging same through a third discharge means;

actuating means operative by actuating fluid received thereby under pressure from said first discharge means of said first pump means for actuating said pressurizing means;

regulator means intermediate said first discharge means and said actuating means for maintaining the said actuating fluid received by said actuating means from said first discharge means at substantially a constant predetermined pressure, thereby maintaining coating composition in said third discharge means likewise at a substantially constant predetermined pressure;

and means for connecting means to said third discharge means for releasing coating composition therefrom in the form of a spray.

8., In a coating composition pressurizing and spraying system, apparatus comprising:

a first pump means including means for Withdrawing actuating fluid from a reservoir containing actuating fluid and discharging same therefrom under pressure through a first discharge means;

14 a second pump means including means for receiving coating composition from a container and discharging same under increased pressure to a second discharge means; pressurizing means for receiving said coating composition from said second pump means through said second discharge means at said increased pressure and discharging same through a third discharge means; said pressurizing means including:

a pressurizing cylinder, a pressurizing piston reciprocably contained in said pressurizing cylinder; actuating means operative by actuating fluid received thereby under pressure from said first discharge means of said first pump means for actuating said pressurizing means; said actuating means including: an actuating cylinder, an actuating piston reciprocably contained in said actuating cylinder, said pressurizing and actuating pistons being interconnected by a common piston rod means for simultaneous reciprocating movement respectively in said pressurizing cylinder and actuating cylinder; pilot valve means; control means actuated by said piston rod means, in-

cluding lost motion means, for shifting said pilot valve means to opposite positions only adjacent the end of each opposite reciprocative travel of said pisto-n rod means; control valve means responsive to said shift of said pilot valve means for complete movement to opposite valving positions upon each said opposite shift of said pilot valve means, said pilot valve, including means for receiving actuating fluid under pressure from said first discharge means and when in one such shiftedposition thereof admitting such actuating fluid under pressure to a first end of said actuating cylinder to urge said actuating piston to move in a direction therein towardthe second end thereof, while permitting discharge of actuating fluid from the second end of said actuating cylinder to such reservoir, and when in the opposite such shifted position admitting such actuating fluid under pres sure to said second end of said actuating cylinder to urge said actuating piston to move in a direction therein toward the first end thereof, while permitting discharge of actuating fluid from said first end of said actuating cylinder to such reservoir; means including valve means operative in connection with said pressurizing cylinder for admitting coating composition under said increased pressure from said third discharge means to a first end of said pressurizing cylinder, whereby said pressurizing piston is urged to move in said pressurizing cylinder toward the second end thereof, and for discharging coating composition under pressure from the second end of said pressurizing cylinder to said third discharge means when said actuating piston and thereby said pressurizing piston is being urged in one direction, as aforesaid; and for admitting coating composition from said third discharge means to said second end of said; pressurizing cylinder whereby said pressurizing piston is urged to move in said pressurizing cylinder toward said first end thereof, and for discharging coating composition under pressure from said first end of said pressurizing cylinder to said third discharge means when said actuating piston and thereby said pressurizing piston is being urged in the other direction, the movement of said pressurizing piston and consequently' the movement of said actuating piston 15 being controlled by and occurring only upon discharge of coating composition from said third discharge means, and means for connecting coating composition release and spray forming means to said third discharge means. v

9. In a coating composition pressurizing and spraying system, apparatuscomprising:

a first pump means including means for withdrawing actuating fluid from a reservoir containing actuating fluid and discharging the same therefrom under pres sure througha first discharge means;

adjustable unloading valve means. including means for interconnecting said first discharge means and such reservoir for bypassing actuating fluid from said first discharge means to said reservoir when the actuating fluid pressure in said first discharge means exceeds a first predetermined value;

a second pump means including means for receiving coating composition from a container and discharging same under increased pressure to a second discharge means;

adjustable unloading valve means interconnecting said second discharge means and such container for continuously circulating coating composition through said second pump means and such container when 'the coating composition in said second discharge means reaches a sec-nd predetermined pressure; pressurizing means for receiving said coating composition from said second pump means through said -second discharge means at saidpredetermined pressure and discharging same through a third discharge means;

said pressurizing means including:

a pressurizing cylinder, 2. pressurizing piston reciprocably contained in said pressurizing cylinder, and

actuating means operative by actuating fluid received thereby under pressure from said first discharge means of said first pump means for actuating said pressurizing means; said actuating means including: an actuating cylinder, an actuating piston reciprocably contained in said actuating cylinder,

said pressurizing and actuating pistons being interconnected by a common piston rod means for simultaneous reciprocating movement respectively in said pressurizing cylinder and actuating cylinder;

pilot valve means;

control means actuated by said piston rod means including lost motion means, for shifting said pilot valve means to opposite positions only adjacent the 7 end of each opposite reciprocated travel of said piston rod means;

, control valve means responsive to said shift of said pilot valve means'for complete movement to opposite valving positions upon each of said opposite shift of said pilot valve means, said pilot valve including means for receiving actuating fluid under pressure from said firstdischarge means and when in one such shifted position thereof admitting such actuating fluid under pressureto a first end of said actuating cylinder to urge said actuating piston to move in a direction therein toward the second end thereof, while permitting discharge of actuating fluid from the sec ond end of said actuating cylinder to such reservoir,

16 and when in the opposite such shifted position permitting such actuating fluid under pressure to said second end of said actuating cylinder to urge said actuating piston to move in a direction therein toward the first end thereof, while permitting discharge of actuating fluid from said first end of said actuating cylinder to such reservoir;

means including valve means operative in connection with said pressurizing cylinder for admitting coating composition under said increased pressure from said third discharge means to a first end of said pressurizing cylinder, whereby said pressurizing piston is urged by said coating composition pressure to move in said pressurizing cylinder toward the second end thereof, and for discharging coating composition under pressure from the second end of said pressurizing cylinder to said third discharge means when said actuating piston and pressurizing piston is being urged in one direction, as aforesaid;

and for admitting coating composition from said third discharge means to said second end of said pressurizing cylinder, whereby said pressurizing piston is urged to move in said pressurizing cylinder toward said first end thereof, and for discharging coating composition under pressure from said first end of said pressurizing cylinder to said third discharge means when said actuating piston and pressurizing piston are being urged in the other direction, as aforesaid;

the movement of said pressurizing piston and consequently the movement of said actuating piston thereby being caused by both the pressure of the actuating fluid and the pressure of the coating composition, and being controlled by and occurring only upon discharge of coating composition from said third discharge means,

and means for connecting coating composition release and spray forming means to said third discharge means.

10. Apparatus in accordance with claim 9 and regulator means intermediate said first discharge means and said actuating means for maintaining said actuating fluid received by said actuating means at substantially a constant predetermined pressure, thereby maintaining coating composition in said third discharge means likewise at a substantially constant predetermined pressure.

11. Apparatus in accordance with claim 9 and regulator means intermediate said first discharge means and said actuating means for maintaining said actuating fluid received by said actuating means at substantially a constant predetermined pressure;

and regulator means in said second discharge means for maintaining said coating composition received by said pressurizing cylinder at substantially constant predetermined pressure,

thereby maintaining coating composition in said third discharge means likewise at a substantially constant predetermined pressure.

References Cited in the file of this patent UNITED STATES PATENTS 2,273,344 Black et a1. Feb. 17, 1942 2,277,569 Vickers far. 24, 1942 2,495,669 Cannon Ian. 24, 1950 2,800,365 Hodges July 23, 1957 2,858,162 Frank Oct. 28, 1958 2,884,860 Ellis et al May 5, 1959 2,928,613 Taylor et al. a", Mar. 15, 1960 

1. IN A COATING COMPOSITION PRESSURIZING AND SPRAYING SYSTEM, APPARATUS COMPRISING: A PUMP MEANS INCLUDING MEANS FOR WITHDRAWING ACTUATING FLUID FROM A RESERVOIR CONTAINING ACTUATING FLUID AND FOR DISCHARGING SAME THEREFROM UNDER PRESSURE THROUGH A FIRST DISCHARGE MEANS; MEANS FOR RECEIVING COATING COMPOSITION FROM A CONTAINER AND CONVEYING SAME UNDER A GIVEN PRESSURE TO A PRESSURIZING INLET MEANS; PRESSURIZING MEANS FOR RECEIVING COATING COMPOSITION FROM SAID PRESSURIZING INLET MEANS AT SAID GIVEN PRESSURE AND SIMULTANEOUSLY DISCHARGING SAME THROUGH A SECOND DISCHARGE MEANS AT AN INCREASED PRESSURE, SAID PRESSURIZING MEANS INCLUDING: A PRESSURIZING INCLUDING: A PRESSURIZING PISTON RECIPROCABLY CONTAINED IN SAID PRESSURIZING CYLINDER; ACTUATING MEANS OPERATIVE BY ACTUATING FLUID RECEIVED THEREBY UNDER PRESSURE FROM SAID FIRST DISCHARGE MEANS OF SAID PUMP MEANS FOR ACTUATING SAID PRESSURIZING MEANS, SAID ACTUATING MEANS INCLUDING: AN ACTUATING CYLINER, AN ACTUATING PISTON RECIPROCABLY CONTAINED IN SAID ACTUATING CYLINDER, 